Special Counsel Robert Mueller has reportedly offered immunity to Democratic lobbyist Tony Podesta in exchange for testimony against Trump campaign chairman Paul Manafort.

Fox News’ Tucker Carlson reported exclusively on Thursday night that two sources confirmed to the network that Podesta was offered immunity to testify against Manafort for a “near identical crime.”

“In other words, for a near identical crime, Bill and Hillary’s friend could escape and emerge completely unscathed while Paul Manafort may rot in jail,” Carlson said. “Only one of them made the mistake of chairing Donald Trump’s presidential campaign.”

Last October, Podesta stepped down from the Podesta Group, an organization that he founded, after it came under investigation by Mueller at the same time that Manafort and Rick Gates were indicted for financial crimes. Politico reported:

The investigation into Podesta and his firm grew out of investigators’ examination of Manafort’s finances. Manafort organized a PR campaign on behalf of a nonprofit called the European Centre for a Modern Ukraine. Podesta Group was one of several firms that were paid to do work on the PR campaign to promote Ukraine in the U.S.

Podesta Group filed paperwork with the Justice Department in April stating that it had done work for the European Centre for a Modern Ukraine that also benefited the same Ukrainian political party that Manafort once advised.

This latest development in Mueller’s Russia investigation may add to the overwhelming allegations of political bias that he has been accused of as his team of prosecutors is comprised of only Democrat prosecutors with no Republicans on his staff.